22 Jan 2024

Amphibious Uncrewed Ground Vehicle for Coastal Surfzone Survey

Abstract: The capability of a commercial off-the-shelf amphibious bottom crawling robot is explored for surveying seamless topography and bathymetry across the beachface, surfzone, and very nearshore. A real-time-kinematic (RTK) antenna on a mast was added to the robotic platform, a Bayonet-350 (previously the C2i SeaOx). Data collected from the robot were compared with those collected by the Coastal Research Amphibious Buggy (CRAB) and the Lighter Amphibious Resupply Cargo (LARC), unique amphibious vessels capable of collecting seamless topography and bathymetry in use for decades at the US Army Engineer Research and Development Center’s Field Research Facility (FRF). Data were compared on five different days in a range of wave conditions (Hs < 1 m in 8-m depth) resulting in a root-mean square difference of 8.7 cm and bias of 2 cm for 24 different cross-shore profile comparisons. Additionally, a repeatability test was performed to assess measurement uncertainty. The repeatability test indicated a total vertical uncertainty (TVU) of 5.8 cm, with the highest spatial error at the shoreline.

21 May 2021

Field Survey to Prioritize Needs for Modernizing Dredged Material Evaluation Guidance

Abstract: This technical note synthesizes and disseminates results of a 2020 survey of USACE dredging program and project managers to identify and prioritize needs related to the modernization and streamlining of the dredged material assessment decision guidance pursuant to Section 404 of the Clean Water Act (CWA) and Section 103 of the Marine Protection Research and Sanctuaries Act (MPRSA). Priorities identified through the survey and subsequent follow-on interviews—together with advances in science and technology—will facilitate development of an electronic decision guidance tool to enable consistent, timely, and cost-effective dredged material management decisions. This tool will also facilitate a standardized database for ready access to historical data.